TEHRAN (FNA)- Researchers from the University of Tehran succeeded in producing Ni-Co/SiC nanostructured coatings with higher adhesive strength and abrasive resistance by using gradual change structures. ( 09:50:55 - 2012/10/29)

The coatings increase the life of pieces posed to abrasion in various industries such as fabrication of airplane and automobile.

Ni-Co/SiC nanostructured coatings have found many applications in various industries due to their high toughness and abrasive resistance, and also due to the fact that they do not poison plating baths. Studies show that reduction in size of the particles significantly decreases adhesive strength of the coating although it extremely increases the toughness, strength, and abrasive resistance. The potential solution to improve adhesion of the coatings is to use gradual change structures.

Pulsed plating process was used in the studies in order to create a homogenous nanostructured coating and gradual change in Ni/SiC and Ni-Co/SiC on the aluminum sub-layer. Ni-SiC and Ni-Co/SiC nanostructured coatings were successfully synthesized simultaneously with the gradual change in the particle size and weight percentage of ceramic particles through gradual increase in the plating current density.

It was observed in the research that the use of gradual change structures improved the adhesive strength and abrasive resistance in the coatings, especially at high abrasive loads, in comparison with the homogenous coatings. In addition, Ni-Co/SiC gradual change nanostructured coatings presented better abrasive behavior comparing to Ni-SiC gradual change nanostructured coatings. The plan is able to be used in the modification of abrasive resistance and corrosion in various pieces in chemical, aerospace, and automobile industries.

Results of the research have been published in Surface and Coatings Technology, vol. 206, issue 19-20, pp. 4032-4039.